All patients aged 16-50 years who had been discharged from the Maudsley Hospital over a 4-year period with a diagnosis of schizophrenia were ascertained retrospectively. Case records were rated blindly for a history of obstetric complications (OCs). Sixty-one patients who satisfied the RDC for schizophrenia had undergone CT scanning. Those with a definite history of OCs presented at an earlier age. In this group widening of cortical sulci and fissures was more strongly correlated with VBR than in subjects without OCs. Moreover, large VBRs when accompanied by widened cortical sulci and fissures occurred more commonly in subjects with OCs than in those without. These results support the hypothesis that OCs, or a factor associated with them, lead to brain damage of aetiological significance in some cases of schizophrenia.